Field of the Invention
The present invention relates to an endoscope, and more particularly to an endoscope including an insertion section whose leading end is provided with a treatment tool elevator (hereinafter referred to simply as an elevator) that controls a leading direction of a treatment tool.
Description of the Related Art
In conventional endoscopes, there are known an ultrasound endoscope and a side-viewing endoscope each of which includes a treatment tool leading section through which various treatment tools inserted from a treatment tool inlet provided in an operation section lead out from their leading ends, and an elevator provided in the treatment tool leading section to control a leading direction of a treatment tool.
In addition, there is known an elevator drive mechanism for driving the elevator, the mechanism using an elevation lever coupled to the elevator with a rotation shaft. This allows operation of an operation lever of an operation section to be transferred to the elevation lever through an operation wire so that the elevation lever is turned to turn the elevator, thereby allowing the elevator to rise and lie (refer to Japanese Patent Application Laid-Open No. 2010-201020 and Japanese Patent Application Laid-Open No. 2004-141315).
In the elevator drive mechanism that uses the elevation lever as described above, a seal member is disposed between an outer wall face of the rotation shaft and an internal wall face of a bearing hole in a partition wall, the bearing hole being used for rotatably supporting the rotation shaft. The seal member forms a sealing surface to prevent blood, water, and the like from entering a lever accommodation space for accommodating the elevation lever from an elevator accommodation space for accommodating the elevator.
In the elevator drive mechanism describe above, it is desirable to integrally form the elevator to be disposed in the elevator accommodation space and a portion of the rotation shaft provided closer to the elevator than the seal member, because if blood or the like enters a connection portion therebetween, time and effort is required for cleaning operation.
Unfortunately, if a portion of the rotation shaft to be an elevator side is formed integrally with the elevator, the elevator and the rotation shaft formed integrally with the elevator need to be inserted into the elevator accommodation space and the bearing hole, respectively, at the same time, in assembly operation of the leading end section.
As a result, a width of the elevator accommodation space needs to be sufficiently more than a width of the elevator to cause a problem of an increase in size of the leading end section. Thus, conventionally, the elevator and the rotation shaft are formed separately.
The present invention is made in light of the above-mentioned circumstances, and has an object to provide an endoscope capable of reducing time and effort required for cleaning operation of an elevator without causing a leading end section to increase in size.